While it is not impossible to meet daily protein requirements through a typical “whole food” diet; some individuals, such as athletes find it hard to consume the 0.45-0.90 grams per pound body weight daily needed to maintain a positive nitrogen balance, optimize muscle growth, and assist recovery efforts. This is the primary reason they supplement as an easy way to meet their protein needs. Furthermore, total daily protein amounts can vary dramatically depending on goals and what sport or activity an individual participates in. A person trying to develop lean muscle for aesthetic or performance reasons will require more protein than a person whose primary purpose is to promote recovery between training sessions. The International Society of Sports Nutrition gives the following guidelines on protein requirements as it relates to different activities and sports. The recommended amounts can be consumed through whole foods sources or in combination with a high-quality supplement such as whey.

Inactive, otherwise healthy adults need this amount of protein due to the constant turnover of cells in the human body and to maintain nitrogen balance. However, consuming higher amounts on a daily basis may confer some benefits. Higher protein consumption has been shown to produce a satiating effect (feeling of fullness). This may lead to decreases in appetite, more stable blood sugar levels, and less total calories eaten daily. Over time this may lead to weight and/or fat loss. Protein also has a higher thermic effect compared to the other macro nutrients. This means it takes more energy to digest and absorb which burns additional calories.

Maintaining a positive nitrogen balance is a key factor in athletes whose sport benefits from having more lean mass while also being able to recover from exercise-induced muscle damage. To maintain this anabolic bodily environment more protein needs to be consumed daily than is broken down. For this reason, athletes whose sports require maximal size, strength and power have the highest protein requirements compared to other individuals. These large amounts are needed to maximize tissue repair, maintain a positive nitrogen balance, promote recovery and optimize the hypertrophic response. Bigger muscles are not only aesthetically pleasing but are also advantageous for athletes who participate in sports such as football. Muscles with greater cross-sectional area can produce stronger and more powerful motions such as pushing, pulling, and sprinting which can directly enhance performance. All in all, individuals who are trying to put on more lean muscle mass should stick to the higher range of this protein recommendation while those trying to maintain can get by with less.

Unlike strength athletes, having more lean mass does not typically benefit aerobic athletes. Additional weight requires more energy to move when efficiency and an ideal strength to weight ratio is key to endurance performance success. Muscle repair and recovery, not growth, are the primary reasons endurance athletes need more protein than inactive individuals but less than strength athletes. In addition to tissue repair, the BCAAs derived from protein consumption can be used as a fuel source during prolonged aerobic activity.

Per the International Society of Sports Nutrition, “where the endurance athlete falls within this recommended range depends on the intensity and duration of the exercise, as well as the training status of the individual. For example, an elite endurance athlete requires a greater intake approaching the higher end of the range. Additionally, as endurance exercise increases in intensity and duration, there is an increased oxidation of branched-chain amino acids, which creates a demand within the body for protein intakes at the upper end of this range.” Practically speaking when endurance training volume is high and intense more protein is required. During lower volume training (such as base training) fewer grams of protein are needed.

Compared to the number of studies that have investigated the protein requirements of strength and endurance athletes, little research exists in regards to the unique protein needs of individuals whose sport requires a combination of strength, endurance and stop and go play. However, the ISSN recommendation of 0.63 – 0.77 grams per pound bodyweight is more than likely sufficient to promote recovery, maintain lean muscle mass, and in some cases, build additional muscle.

Protein Requirements for Individuals Restricting Calories and Vegetarians
On a gram for gram basis, plant-based proteins yield less total protein and essential amino acids compared to sources such as milk or meat. For this reason, it is recommended athletes who follow a vegetarian/vegan diet consume ~0.90 grams of protein per pound body weight daily to aid muscle growth and repair. Similarly, those on a calorie-restricted diet should also up protein intake to ~0.90 grams per pound body weight to preserve lean muscle mass.

Bottom Line on Requirements
General protein recommendations for inactive individuals are 10-15% of total daily calories or 0.36 grams per pound body weight. This amount, however, differs for people who participate in strength, endurance, or intermittent sports. As a general guideline, the International Society of Sports Nutrition (ISSN) recommends “that exercising individuals ingest protein ranging from 0.63 to 0.90 grams per pound body weight daily. People engaging in endurance exercise should ingest levels at the lower end of this range, individuals engaging in intermittent activities should ingest levels in the middle of this range, and those engaging in strength/power exercise should ingest levels at the upper end of this range.”